Chris Browndidn't let Seth MacFarlane's joke about his controversial relationship with Rihanna stop him from having a good time Sunday night. The singer, 23, attended Elton John's AIDS Foundation 21st annual Academy Awards Viewing party at The City of West Hollywood Park without his on-again, off-again girlfriend.

An insider tells Us Weekly that Brown was "bombarded" by fans wanting to take pictures and he was more than happy to oblige. "He was loving it and saying yes to everybody," and insider tells Us. "He told a tall blonde woman who asked for a photo, 'You're gorgeous.'"

"Chris was smiling and extremely kind with everyone," an eyewitness adds of the "Don't Wake Me Up" crooner. "He looked really cheerful and flattered to have so many guests approaching him."

After chain-smoking near the bathroom, an insider tells Us Brown got even more lively when he headed over to the bar. "He was the life of the party" the eyewitness tells Us, noting that Brown was talking "non-stop" and "super-social" with other revelers. "He looked so happy to be getting such positive attention from guests."